Serial Interface - ero electronic LFS Manuel De Service

VOLTAGE OUTPUTS FOR SSR DRIVE VOLTAGE OUTPUTS FOR SSR DRIVE VOLTAGE OUTPUTS FOR SSR DRIVE VOLTAGE OUTPUTS FOR SSR DRIVE VOLTAGE OUTPUTS FOR SSR DRIVE
(For LFS-relay only) (For LFS-relay only) (For LFS-relay only) (For LFS-relay only) (For LFS-relay only)
+
6
+
OUT 1
_ _ _ _ _ _
7
SOLID STATE
RELAY
Fig. 11 SSR DRIVE OUTPUT WIRING
It is a time proportioning output.
Logic level 0 Logic level 0 Logic level 0 Logic level 0 Logic level 0: Vout < 0.5 V DC.
Logic level 1 Logic level 1 Logic level 1 Logic level 1 Logic level 1:
- 14 V + 20 % @ 20 mA
- 24 V + 20 % @ 1 mA.
Maximum current = 20 mA.
NOTE NOTE NOTE NOTE NOTE: This output is not isolated. A double or
reinforced isolation between instrument output
and power supply must be assured by the
external solid state relay.
LFS-1-CC.P65 7

SERIAL INTERFACE

SERIAL INTERFACE SERIAL INTERFACE SERIAL INTERFACE SERIAL INTERFACE
RS-485 interface allows to connect up to 30
devices with one remote master unit.
I
A/A'
N
11
S
T
B/B'
R
12
U
M
COMMON
E
13
N
T
Fig. 12 - RS-485 WIRING
The cable length must not exceed 1.5 km at 9600
BAUD.
NOTE NOTE NOTE: 1) This is an RS485 isolated interface.
NOTE NOTE
2)The following report describes the
signal sense of the voltage appearing
across the interconnection cable as
defined by EIA for RS-485.
a) The " A " terminal of the generator shall
be negative with respect to the " B "
terminal for a binary 1 (MARK or OFF)
state.
b) The " A " terminal of the generator shall
be positive with respect to the " B "
terminal for a binary 0 (SPACE or ON)
GB GB
GB GB GB 7
13/07/2004, 14:40
A'/A
M
A
B'/B S
T
E
R